Your age is not a problem, myself and a few others started training at 18 almost straight from school, give or take 6 months. Having a uni degree is a nice thing to have, especially if you lose your medical etc, but its not essential for an airline job.
I think the airlines are more concerned about you having the basic fATPL/IR etc and being confident, mature, team player etc etc with it.
Like that army ad says, Quality means more than qualifications or something.
My only regret about not doing uni is probably the social scene, independence, more than the actual degree itself.